Ekpson R3000 leaves 1/4" blank on 13x19

I have started to make 13x19" prints on my Epson R3000. However, the printer leaves the last 1/4" blank. I believe I am loading the paper properly, using the front loading tray with the front edge of the paper lined up with the groove that is close to the front edge of said loading tray. I am printing on Epson Exhibition Fiber Paper. Btw, aside from this problem, I love the prints. I have had no problems with 4x6 or letter size prints.